KGB messenger CTF challenge | Alerts (Medium)

アプリケーションの実行時にロシアのデバイスでのみ実行される通知ウィンドウは少ない

.method protected onCreate(Landroid/os/Bundle;)V
    .locals 3

    invoke-super {p0, p1}, Landroid/support/v7/app/c;->onCreate(Landroid/os/Bundle;)V

    const v0, 0x7f09001c

    invoke-virtual {p0, v0}, Lcom/tlamb96/kgbmessenger/MainActivity;->setContentView(I)V

    const-string v0, "user.home"

    invoke-static {v0}, Ljava/lang/System;->getProperty(Ljava/lang/String;)Ljava/lang/String;

    move-result-object v0

    const-string v1, "USER"

    invoke-static {v1}, Ljava/lang/System;->getenv(Ljava/lang/String;)Ljava/lang/String;

    move-result-object v1

    if-eqz v0, :cond_0

    invoke-virtual {v0}, Ljava/lang/String;->isEmpty()Z

    move-result v2

    if-nez v2, :cond_0

    const-string v2, "Russia"

    invoke-virtual {v0, v2}, Ljava/lang/String;->equals(Ljava/lang/Object;)Z

    move-result v0

    if-nez v0, :cond_1

    :cond_0
    const-string v0, "Integrity Error"

    const-string v1, "This app can only run on Russian devices."

    invoke-direct {p0, v0, v1}, Lcom/tlamb96/kgbmessenger/MainActivity;->a(Ljava/lang/String;Ljava/lang/String;)V

    :goto_0
    return-void

    :cond_1
    if-eqz v1, :cond_2

    invoke-virtual {v1}, Ljava/lang/String;->isEmpty()Z

    move-result v0

    if-nez v0, :cond_2

    invoke-virtual {p0}, Lcom/tlamb96/kgbmessenger/MainActivity;->getResources()Landroid/content/res/Resources;

    move-result-object v0

    const/high16 v2, 0x7f0d0000

    invoke-virtual {v0, v2}, Landroid/content/res/Resources;->getString(I)Ljava/lang/String;

    move-result-object v0

    invoke-virtual {v1, v0}, Ljava/lang/String;->equals(Ljava/lang/Object;)Z

    move-result v0

    if-nez v0, :cond_3

    :cond_2
    const-string v0, "Integrity Error"

    const-string v1, "Must be on the user whitelist."

    invoke-direct {p0, v0, v1}, Lcom/tlamb96/kgbmessenger/MainActivity;->a(Ljava/lang/String;Ljava/lang/String;)V

    goto :goto_0

    :cond_3
    invoke-static {p0}, La/a/a/a/a;->a(Landroid/content/Context;)V

    new-instance v0, Landroid/content/Intent;

    const-class v1, Lcom/tlamb96/kgbmessenger/LoginActivity;

    invoke-direct {v0, p0, v1}, Landroid/content/Intent;-><init>(Landroid/content/Context;Ljava/lang/Class;)V

    invoke-virtual {p0, v0}, Lcom/tlamb96/kgbmessenger/MainActivity;->startActivity(Landroid/content/Intent;)V

    goto :goto_0
.end method

apktool b kgb-messenger -o kgb-re.apk

java -jar signapk.jar testkey.x509.pem testkey.pk8 kgb-re.apk kgb-re-sign.apk

Passwordは来賓です